by Mike Meehan

Whether it’s grassy plains, picturesque mountains or lush forests, trail running allows us to connect with nature. While there are many opportunities to enjoy nature’s beauty above ground, very few runners experience nature’s underground treasures. The Sand Mine Challenge, held in Crystal City, Missouri, is one of just a few off-road races in the country to venture into the depths of the Earth.

Located 35 miles south of St. Louis, Crystal City was at the center of the glass industry from the mid-1800’s to late 1900’s. For more than 100 years, the local mine supplied sandstone to the area’s glass manufacturers including what was once the world’s largest plate-glass manufacturing plant.

Extracting the sandstone created a network of tunnels crisscrossing over 200 acres—all of which still exist today. With 30-to40-foot ceilings held up by thick rock pillars, some areas are cramped and narrow, while others expand into cavernous passages. And, hidden deep within the mine is a 150-acre lake. The mine’s soft, sand floor, pools of standing water and monumental stone pillars create a tranquil environment.

Along the four-mile course participants run over rocks, and wade through sand and water. “The sand is pulling you down the whole time,” says Wunder. Runners also face other obstacles. Says Katrina Pon, a three-time Ironman finisher who has competed in both editions of the Sand Mine Challenge, “You be running along and all of sudden have to climb over a mountain of dirt, run through a pool of knee-deep water or jump over a hurdle.” The mine is partially illuminated with electric lights, however, most runners wear headlamps to help them navigate the course.

Over 730 people participated in this year’s race, held on February 25, 2012. “All you hear from participants is how awesome and unique it is. Where else can you run through a mine?” Wunder says. The mine’s varying water levels cause erosion and other changes to its interior over time forcing the course to be altered each year. “There’s no telling what the course will look like next year,” says Wunder.